1.Why do electricity supply companies include fixed charges in their accounts for
electricity? 2.What is an ‘off-peak tariff’? Explain the structure of the Economy 7 and Economy
10 tariffs, and describe the pattern of demand from a domestic consumer who could be expected to opt for such tariffs. 3.Why may an electricity supply company or a consumer decide that a coin or token prepayment meter should be used in a particular installation?